In order to improve the access speed of a memory device, a burst mode access function can be provided for the memory device. A burst mode access read of the memory device can start at any memory location and can continue for any number of memory locations. In such a memory, any number of memory locations, not only groups of four memory locations, can be read consecutively in burst mode. Sequential memory access is consequently quite fast.
In an example, the burst mode access is provided as follows. The memory array is divided into two memory banks. Each memory bank includes half of the columns of the memory array. Each memory bank has its own row and column decoders that can access the corresponding memory bank independent of the other side. The columns of each memory bank are divided into predetermined groups of columns. A sense amplifier circuit is provided for each group in each memory banks.
In accordance with burst mode access, data in the memory banks is sensed through the corresponding sense amplifier circuits simultaneously. Data thus sensed from both memory banks is held in data registers. First, data from the data register corresponding to one memory bank is transferred to the exterior. Then, data from the data register corresponding to the other memory bank is transferred to the exterior, and, at the same time, data is sensed from the next location in the first memory bank, through its attached sense amplifier circuit.
An example of a memory device with an above-mentioned burst mode access is disclosed in U.S. Pat. No. 5,559,990, entitled MEMORIES WITH BURST MODE ACCESS, which is incorporated by reference herein.
It is well known in the art that power noise (often referred to as "input/output (IO) noise") accompanies data output signaling. If data in one memory bank is sensed at the same time that data corresponding to another memory bank is being output, the data sensing operation may be affected by power noise. As a result, it is impossible to ensure a stable data sensing operation for a memory device during burst mode access.